Wizard Detective
by hp-ss4eva
Summary: harry was taken from his relative's doorstep and was given to the Holmes family, they adopt him and he becomes Sherlock Holmes. Found at the age of 11 he goes to Hogwarts. How will this effect the war? Harry!Sherlock Holmes/John Watson
1. Prologue

Author's note: Disclaimer: I do not own Harry Potter or Sherlock.

 **Prologue – The Beginning**

Privet Drive an ordinary suburban street in Surry with ordinary middle class people who pretend to be a higher social standard than others was the last place you would expect for there to be any strange occurrence, the most exciting thing to happen is when a next door neighbour hosts a party to show off a new expensive work car that was actually much less than they say, but the night of Halloween in 1981 that was all going to change with the arrival of a strange man with a baby. The only person to witness the happenings was a man blending in with the shadows around him. He was here for a purpose and it was watching the strangely dressed man that he realised his job was more important than he realised.

Nothing like this man had ever been seen in Privet drive, tall, thin and very old with hair and beard long enough to tuck in his belt. Wearing a long red robe with silver stars on, a purple cloak that pooled along the ground and high-heeled, buckled boots. He had blue eyes that twinkled behind half-moon spectacles, giving off a façade of a grandfatherly type person who any and all can trust. This however was a ruse behind the twinkling eyes hidden just enough was deceit, and calculating eyes trying to figure out how to manipulate what was in front of him so he could come out on top. His name was Albus Dumbledore.

He was here to deliver the boy-who-lived to the last of his remaining family, what did it matter to him weather the boy was hated by his jealous aunt and her family knowing only disdain and hatred, who cared that it went against the wills of his parents or broke him, so long as he could manipulate the boy into being his pawn in the war none of it mattered. The brat would love him for saving him from his relatives at the age of 11 then a bit of careful manipulation and he would be a hero in the eyes of the brat. He would need a cover story as to why he is leaving the boy here. Blood wards the answer to that question and also ensures that he would have to go back each summer to keep up appearances and him downtrodden.

The hidden man watched as a cat on the wall near number 8 jumped and turned into a strict looking woman dressed in both black and emerald green and the two interacted, waiting for something to happen which was the baby being placed on the doorstep of number 4 Privet Drive. He stayed hidden until the pair had disappeared.

Slowly he walked in to the light of number 4 he had long midnight black hair, pale nearly translucent skin and a light brown green mix for eyes he was looking down at the bundle of blankets which held the sleeping baby. Gently he bends over the child and picks him up seeing the note he reads it

Mr and Mrs Dursley,

Petunia your sister was murdered during the night, along with her husband, leaving your nephew with nowhere else to go. He is a magical child and will be attending Hogwarts at the age of 11. It is up to you on what you tell him and when. I would appreciate it if you could take the boy in as he needs the protection of the blood you carry. On a side note I believe that you hold the thought that you must earn your keep, and in strong discipline also, this will not be a problem and I can guarantee that there will be no interference from the wizarding world. He will be with you until at least the age of 17. Sorry for your loss.

Regards

Albus Dumbledore

(Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)

"Hmm, come on then little one, let's get you to safety" he finally speaks as he turns around and walks away to a car parked at the end of the road. It is one where the windows are tinted almost black indicating someone of importance owns the vehicle. Sliding in to the back, he states "Sherrinford's" as the car pulls away.

They arrive at the large ornate gates made of strong malleable iron painted black. The guard at the front stops them to do the normal cursory check, stopping to say hello, before waving them through.

It takes ten minutes to arrive at the house which closely resembles a giant mansion more than a house; he exits the car and walks up the stairs leading to the front door which opens just as he reaches it. Stopping only to say

"Thank you James, please alert Mr Holmes I am in urgent need of his presence"

"Of course sir, he will be there presently"

~~~~~~~~~~~ Sherlock/Harry Potter ~~~~~~~~~~~

Sherrinford Holmes entered the study, to see an old acquaintance, Victor Trent. Intrigued he took the time to sit in his chair too deduce what it was about the child he held, as this was undoubtedly what this impromptu visit was about. Taking in the moving image on the blanket (magical child) and the note clenched tightly in the hand connected to a very tense body (orphaned/abandoned), dirt on bottom of the blanket, no dirt on Victor's front or sides, small pieces of gravel under his fingertips, rumpled shirt (doorstep, bent down to pick up, unable to straighten clothes due to holding note and baby) conclusion the baby was abandoned/orphaned left on a doorstep, found by Victor who then read the note and resulted in bringing the child here.

"Sherrinford I know you have most likely figured it out by now so I shall just hand the note to you; see what you make of it"

"Hmm, little empathy towards the family most likely disdain with the way he just blurts it out, most would say 'I regret to tell you' or something along that line, words like magical, Hogwarts and the titles of the man paired with the lines you must earn your keep and strong discipline with no interference is a subtle way of saying you magic haters, here's a magical baby, raise him how you want no problem. Tries to justify it by saying he needs protection only blood can give and further antagonises them with the till he's 17 part. Conclusion the sender's an old man who is trying to uphold a façade of a grandfatherly figure whilst manipulating those around him, most likely it would have seemed as though he was saving the boy from his horrid relatives causing the abused at least verbally boy to hero worship him for being the first kind adult he would encounter, this child would most likely have had a very short and miserably life"

"Thank you, doubt I would have known all that without you. The question now however is what do we do with him now?"

"He can stay here. Clara and I will adopt him, we have Mycroft he could do with a younger brother, and I have a feeling that he needs to be prepared for the future and what better way than to grow up a Holmes besides he must be pretty important to have his life manipulated by this Albus Dumbledore"

"Really, you're going to take him in as a son? He'll need a new name"

"Pass him here, let's see him"

Victor passes the now awake Harry over to Sherrinford who look at each other intently, Harry's eyes narrowing slightly in concentration as they study each other. Slowly a smile spreads across Sherrinford's face as Harry turns away seemingly bored he states

"Sherlock, Sherlock Holmes"

Looking to the other man he continues "is there any other business you need to take care off?"

"No, no I have to be getting off; I'm late enough as it is we will sort the papers out at a later date easily enough. I'll see myself out and good luck"

"Yes, you too, see you at the usual time we'll sort legalities out then."

The last thing Victor Trent hears is Sherrinford calling his wife Clara and his now eldest son to come meet the new member of his family"

~~~~~~~~~~~ Sherlock/Harry Potter ~~~~~~~~~~~

Two weeks later Victor Trent was dredged up from the bottom of the river Thames, cause of death believed to be suicide due to being recently bankrupt and unable to face his wife and children. The case was closed and completely forgotten about, so no one but the Holmes family and help knew that young master Sherlock was adopted, and as the help loved their employers they never gave away secrets.

There was no mention of Victor Trent in the Holmes family until Sherlock's 5th birthday and that night Sherlock snuck away to the local cemetery. The morning after Sherlock was the proud new owner of a skull courtesy of Victor Trent, which he used to bounce new ideas and deductions at.


	2. Chapter 1

**Chapter 1 – 10 Years Later**

Time passed quickly for the Holmes family. Sherlock grew into a curious, emotionally detached soon to be 11-year-old boy. He was classed a high-functioning sociopath at the age of 3 and a genius at the age of 4. He started to deduce things during his 3rd year of living with his new family.

You could usually find Sherlock in either the laboratory, set up when he was aged 8 where he conducted a lot of his experiments. This included a microwave and a fridge, from the time that Cook found a cat's head in one and mould in the other, when called down for an explanation his excuse was:

"I am conducting an experiment on the coagulation of cat saliva after death and another on what happens when the mould Stachybotrys chartarum or black mould is exposed to heat after a growing period of 6 days in optimum conditions."

Or the library, where he usually read books on forensics or others which contained useful facts he would need later on in life. He also spent a lot of time in London so that by the time he was 6 he had memorised the name of every street and could visualise the quickest/longest/etc. route to take to get from point A to B using markers on streets and well known buildings and signs.

He got bored often and was insufferable to anyone he did not like or know and held a strange relationship with his family, especially, with his brother. Him and Mycroft fought like there was no tomorrow, trying to outwit each other with their intelligence.

Yet when tragedy strikes, like when their father died. Sherlock was 7 at the time, and adored the man. He was the one who taught him nearly everything he knew. They become protective of each other. Mycroft more so than Sherlock as he believed it was his responsibility, as the man of the house, as he was now the eldest man alive in the family.

Soon though everything went back to normal with the insults flying, except with one major difference, now when one of his experiments goes wrong, Mycroft is the one who sorts the mess out, or when Sherlock was being bullied during school, it was Mycroft, who got him boxing and defence lessons or came into school when needed, because, he was caught experimenting or deducing the teachers, parents and other class mates, he also got Sherlock a tutor for the violin, when he expressed a wish to learn.

His mother had a strained relationship with him, knowing it was because he was adopted and she forced in to accepting it, she had always treated Mycroft as the better son and was always disappointed about how Sherlock was with emotions. Not understanding what is and is not appropriate to say at certain times, this caused him to be socially inept, saying what is on his mind during social gatherings after deducing their guest's whole life story. Usually reducing them to tears after saying something along the lines of 'he's having an affair with her' or vice versa.

Sherlock was a very independent person from a young age, he was able to do most things for himself from the age of 3, he was told everything about his past, before becoming a Holmes on his 5th birthday, he was shown the letter where he proceeded to make the same deductions his father had, 5 years previously.

Sherlock is cut from his musings when Mycroft entered the lab. Glaring at him as he observed what Mycroft wanted. His brother stared calmly back, smiling slightly at the usual response, walking in to a room with Sherlock present in gained,

Sherlock's POV

"I take it mummy wishes to see me" it was more of a statement than a question he already knew.

"Indeed, brother dear in th…" I cut off as I speak over him

"The drawing room, yes, yes I know. How's the diet, snuck in behind Cook's back yet" when in need of an insult use his weight.

"Very well thank you, and no, leg works your forte, I will leave that up to you. Make an experiment of it"

"Boring, I did that years ago, it was spectacularly easy, I managed to escape with most of the sweet stash you had hidden" I smile up at him as Mycroft realises exactly which stash I am talking about.

I become bored with just listening to him, so I try to ignore him, returning to my experiment, to find that too much heat has been added to the plastic causing it to melt way past what I needed. Blast. I pick it up and chuck it in the bin next to my work space.

"So that's where it went, I was so wondering. You turn 11 tomorrow; the wizarding world will not leave you alone; the letter attested to that. What are you going to do?"

"Not, that it's any of your business. But I'm going to play along and observe, whilst acting myself. How I wish I had my violin right now, you ruined my experiment."

"Such a shame. Well then I wish you luck on your endeavour and may I say, I very nearly pity those who abandoned you. I'll ensure you have a working phone, far be it me who unleashes a Sherlock with no forms of communication, in to the midst of those at Hogwarts. Don't forget mummy."

"Do try not to start any wars this afternoon you know what it does to traffic"

"Very funny"

I wait until I know Mycroft has gone before I restart the experiment I was conducting. Mummy can wait.

~~~~~~~~~~~ Sherlock/Harry Potter ~~~~~~~~~~~

Clara Holmes POV

Ms Clara Holmes, mother to Mycroft and Sherlock, was sat in one of the high-backed chairs, thinking on her late husband, the sudden and unexpected death of her husband, Sherrinford Holmes had hit her hard; the once joyful, happy woman had become a cold and emotionless husk when around others, with the exception of her sons and the help.

She wore the finest clothes money could buy, had on perfect make-up and her long golden hair was woven in to one of the most elaborate hairstyles with curls and grips. In short she was the perfect example of a high socialite, which of course, she was, being one of the richest in the world; she had 2 geniuses as sons, in whom one was basically the British government, MI5, Secret Service or any other department he needs at the time, yet when asked, will say he holds a minor position in the British Government.

A knock on the door announced the arrival of Sherlock. As he entered the room she watched as he observed her, smiling when he finally spoke.

"Your upset mummy"

"Yes Sherlock, I've been thinking about your father"

She watched the barest flicker of pain cross his face at the mention of his father disappearing so fast she could believe that most would say she imagined it; she however was not most people. How she worried about her adoptive son. Unable to understand emotions and deal with situations that involved them, she knows he chooses to ignore them completely, as seen in his next statement.

"Mycroft said you wished to see me."

"Yes your birthday is tomorrow. Friends and family will be visiting. You will behave. I do not want a repeat of what happened last time. There will be no experiments involving recently dead animals and knives. I still don't know how you got hold of them. Also there will also be no deducing who's sleeping with whom, causing yet more breakdowns. And you will most defiantly not show up covered in blood again; people thought you had killed someone."

"It was cow's blood; it's not my fault people cannot differentiate between the two."

"That's not the point, Sherlock; the point is that you almost gave several people heart attacks with your sudden appearance whilst covered in blood. Ambulances needed to be called, because more than half were in shock and at least 2 were sent to hospital."

"Very well mummy I will try to refrain from conducting any experiments, involving things like blood."

Relief washes over her, after that statement, she will be fine, he has said he will try that was something, on the other hand, he was Sherlock so she will continue to be cautious, _I must remember to get someone to run through his lab before the guests arrive, just to double check._

"Thank you, now like your brother before you did, you will be going to a boarding school at the start of this academic year. Do you know where you wish to go?"

"Yes, Hogwarts, mummy, I believe I will have very little choice in the matter, I doubt they would leave me alone unless I do"

"Yes, you're correct, I saw the letter. Very well, you may go."

"Yes mummy, shall I send James in?"

"Please if you wouldn't mind, thank you."


End file.
